Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397/* SPDX-License-Identifier: GPL-2.0 */#ifndef _LINUX_BITOPS_H#define _LINUX_BITOPS_H
#include <asm/types.h>#include <linux/bits.h>#include <linux/typecheck.h>
#include <uapi/linux/kernel.h>
#define BITS_TO_LONGS(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(long))#define BITS_TO_U64(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u64))#define BITS_TO_U32(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(u32))#define BITS_TO_BYTES(nr) __KERNEL_DIV_ROUND_UP(nr, BITS_PER_TYPE(char))
#define BYTES_TO_BITS(nb) ((nb) * BITS_PER_BYTE)
extern unsigned int __sw_hweight8(unsigned int w);extern unsigned int __sw_hweight16(unsigned int w);extern unsigned int __sw_hweight32(unsigned int w);extern unsigned long __sw_hweight64(__u64 w);
/* * Defined here because those may be needed by architecture-specific static * inlines. */
#include <asm-generic/bitops/generic-non-atomic.h>
/* * Many architecture-specific non-atomic bitops contain inline asm code and due * to that the compiler can't optimize them to compile-time expressions or * constants. In contrary, generic_*() helpers are defined in pure C and * compilers optimize them just well. * Therefore, to make `unsigned long foo = 0; __set_bit(BAR, &foo)` effectively * equal to `unsigned long foo = BIT(BAR)`, pick the generic C alternative when * the arguments can be resolved at compile time. That expression itself is a * constant and doesn't bring any functional changes to the rest of cases. * The casts to `uintptr_t` are needed to mitigate `-Waddress` warnings when * passing a bitmap from .bss or .data (-> `!!addr` is always true). */#define bitop(op, nr, addr) \ ((__builtin_constant_p(nr) && \ __builtin_constant_p((uintptr_t)(addr) != (uintptr_t)NULL) && \ (uintptr_t)(addr) != (uintptr_t)NULL && \ __builtin_constant_p(*(const unsigned long *)(addr))) ? \ const##op(nr, addr) : op(nr, addr))
/* * The following macros are non-atomic versions of their non-underscored * counterparts. */#define __set_bit(nr, addr) bitop(___set_bit, nr, addr)#define __clear_bit(nr, addr) bitop(___clear_bit, nr, addr)#define __change_bit(nr, addr) bitop(___change_bit, nr, addr)#define __test_and_set_bit(nr, addr) bitop(___test_and_set_bit, nr, addr)#define __test_and_clear_bit(nr, addr) bitop(___test_and_clear_bit, nr, addr)#define __test_and_change_bit(nr, addr) bitop(___test_and_change_bit, nr, addr)
#define test_bit(nr, addr) bitop(_test_bit, nr, addr)#define test_bit_acquire(nr, addr) bitop(_test_bit_acquire, nr, addr)
/* * Include this here because some architectures need generic_ffs/fls in * scope */#include <asm/bitops.h>
/* Check that the bitops prototypes are sane */#define __check_bitop_pr(name) \ static_assert(__same_type(arch_##name, generic_##name) && \ __same_type(const_##name, generic_##name) && \ __same_type(_##name, generic_##name))
__check_bitop_pr(__set_bit);__check_bitop_pr(__clear_bit);__check_bitop_pr(__change_bit);__check_bitop_pr(__test_and_set_bit);__check_bitop_pr(__test_and_clear_bit);__check_bitop_pr(__test_and_change_bit);__check_bitop_pr(test_bit);__check_bitop_pr(test_bit_acquire);
#undef __check_bitop_pr
static inline int get_bitmask_order(unsigned int count){ int order;
order = fls(count); return order; /* We could be slightly more clever with -1 here... */}
static __always_inline unsigned long hweight_long(unsigned long w){ return sizeof(w) == 4 ? hweight32(w) : hweight64((__u64)w);}
/** * rol64 - rotate a 64-bit value left * @word: value to rotate * @shift: bits to roll */static inline __u64 rol64(__u64 word, unsigned int shift){ return (word << (shift & 63)) | (word >> ((-shift) & 63));}
/** * ror64 - rotate a 64-bit value right * @word: value to rotate * @shift: bits to roll */static inline __u64 ror64(__u64 word, unsigned int shift){ return (word >> (shift & 63)) | (word << ((-shift) & 63));}
/** * rol32 - rotate a 32-bit value left * @word: value to rotate * @shift: bits to roll */static inline __u32 rol32(__u32 word, unsigned int shift){ return (word << (shift & 31)) | (word >> ((-shift) & 31));}
/** * ror32 - rotate a 32-bit value right * @word: value to rotate * @shift: bits to roll */static inline __u32 ror32(__u32 word, unsigned int shift){ return (word >> (shift & 31)) | (word << ((-shift) & 31));}
/** * rol16 - rotate a 16-bit value left * @word: value to rotate * @shift: bits to roll */static inline __u16 rol16(__u16 word, unsigned int shift){ return (word << (shift & 15)) | (word >> ((-shift) & 15));}
/** * ror16 - rotate a 16-bit value right * @word: value to rotate * @shift: bits to roll */static inline __u16 ror16(__u16 word, unsigned int shift){ return (word >> (shift & 15)) | (word << ((-shift) & 15));}
/** * rol8 - rotate an 8-bit value left * @word: value to rotate * @shift: bits to roll */static inline __u8 rol8(__u8 word, unsigned int shift){ return (word << (shift & 7)) | (word >> ((-shift) & 7));}
/** * ror8 - rotate an 8-bit value right * @word: value to rotate * @shift: bits to roll */static inline __u8 ror8(__u8 word, unsigned int shift){ return (word >> (shift & 7)) | (word << ((-shift) & 7));}
/** * sign_extend32 - sign extend a 32-bit value using specified bit as sign-bit * @value: value to sign extend * @index: 0 based bit index (0 <= index < 32) to sign bit * * This is safe to use for 16- and 8-bit types as well. * * Return: 32-bit sign extended value */static __always_inline __s32 sign_extend32(__u32 value, int index){ __u8 shift = 31 - index; return (__s32)(value << shift) >> shift;}
/** * sign_extend64 - sign extend a 64-bit value using specified bit as sign-bit * @value: value to sign extend * @index: 0 based bit index (0 <= index < 64) to sign bit * * This is safe to use for 32-, 16- and 8-bit types as well. * * Return: 64-bit sign extended value */static __always_inline __s64 sign_extend64(__u64 value, int index){ __u8 shift = 63 - index; return (__s64)(value << shift) >> shift;}
static inline unsigned int fls_long(unsigned long l){ if (sizeof(l) == 4) return fls(l); return fls64(l);}
static inline int get_count_order(unsigned int count){ if (count == 0) return -1;
return fls(--count);}
/** * get_count_order_long - get order after rounding @l up to power of 2 * @l: parameter * * it is same as get_count_order() but with long type parameter */static inline int get_count_order_long(unsigned long l){ if (l == 0UL) return -1; return (int)fls_long(--l);}
/** * parity8 - get the parity of an u8 value * @val: the value to be examined * * Determine the parity of the u8 argument. * * Returns: * 0 for even parity, 1 for odd parity * * Note: This function informs you about the current parity. Example to bail * out when parity is odd: * * if (parity8(val) == 1) * return -EBADMSG; * * If you need to calculate a parity bit, you need to draw the conclusion from * this result yourself. Example to enforce odd parity, parity bit is bit 7: * * if (parity8(val) == 0) * val ^= BIT(7); */static inline int parity8(u8 val){ /* * One explanation of this algorithm: * https://funloop.org/codex/problem/parity/README.html */ val ^= val >> 4; return (0x6996 >> (val & 0xf)) & 1;}
/** * __ffs64 - find first set bit in a 64 bit word * @word: The 64 bit word * * On 64 bit arches this is a synonym for __ffs * The result is not defined if no bits are set, so check that @word * is non-zero before calling this. */static inline __attribute_const__ unsigned int __ffs64(u64 word){#if BITS_PER_LONG == 32 if (((u32)word) == 0UL) return __ffs((u32)(word >> 32)) + 32;#elif BITS_PER_LONG != 64#error BITS_PER_LONG not 32 or 64#endif return __ffs((unsigned long)word);}
/** * fns - find N'th set bit in a word * @word: The word to search * @n: Bit to find */static inline unsigned int fns(unsigned long word, unsigned int n){ while (word && n--) word &= word - 1;
return word ? __ffs(word) : BITS_PER_LONG;}
/** * assign_bit - Assign value to a bit in memory * @nr: the bit to set * @addr: the address to start counting from * @value: the value to assign */#define assign_bit(nr, addr, value) \ ((value) ? set_bit((nr), (addr)) : clear_bit((nr), (addr)))
#define __assign_bit(nr, addr, value) \ ((value) ? __set_bit((nr), (addr)) : __clear_bit((nr), (addr)))
/** * __ptr_set_bit - Set bit in a pointer's value * @nr: the bit to set * @addr: the address of the pointer variable * * Example: * void *p = foo(); * __ptr_set_bit(bit, &p); */#define __ptr_set_bit(nr, addr) \ ({ \ typecheck_pointer(*(addr)); \ __set_bit(nr, (unsigned long *)(addr)); \ })
/** * __ptr_clear_bit - Clear bit in a pointer's value * @nr: the bit to clear * @addr: the address of the pointer variable * * Example: * void *p = foo(); * __ptr_clear_bit(bit, &p); */#define __ptr_clear_bit(nr, addr) \ ({ \ typecheck_pointer(*(addr)); \ __clear_bit(nr, (unsigned long *)(addr)); \ })
/** * __ptr_test_bit - Test bit in a pointer's value * @nr: the bit to test * @addr: the address of the pointer variable * * Example: * void *p = foo(); * if (__ptr_test_bit(bit, &p)) { * ... * } else { * ... * } */#define __ptr_test_bit(nr, addr) \ ({ \ typecheck_pointer(*(addr)); \ test_bit(nr, (unsigned long *)(addr)); \ })
#ifdef __KERNEL__
#ifndef set_mask_bits#define set_mask_bits(ptr, mask, bits) \({ \ const typeof(*(ptr)) mask__ = (mask), bits__ = (bits); \ typeof(*(ptr)) old__, new__; \ \ old__ = READ_ONCE(*(ptr)); \ do { \ new__ = (old__ & ~mask__) | bits__; \ } while (!try_cmpxchg(ptr, &old__, new__)); \ \ old__; \})#endif
#ifndef bit_clear_unless#define bit_clear_unless(ptr, clear, test) \({ \ const typeof(*(ptr)) clear__ = (clear), test__ = (test);\ typeof(*(ptr)) old__, new__; \ \ old__ = READ_ONCE(*(ptr)); \ do { \ if (old__ & test__) \ break; \ new__ = old__ & ~clear__; \ } while (!try_cmpxchg(ptr, &old__, new__)); \ \ !(old__ & test__); \})#endif
#endif /* __KERNEL__ */#endif